流体隔振浮筏实验与最优减振液面控制研究

硕士学位论文AbstractVibration isolation and noise reduction is a problem has been widely concernedin the field of academic research and engineering application and people to it of therequest is higher and higher.Traditional linear damped systems have goodperformance of high-frequency vibration isolation.However,when meet thelow-frequency vibration its have not good performance any more due to the structureof itself.In recent years,some new types of low-frequency vibration isolation theoryand device have been established such as quasi-zero-stiffness,dynamic vibrationabsorber,inertia coupling antisonance vibration isolation and fluid raft antiresonancevibration isolator.In this paper,the theoretical vibration isolation characteristics of the fluidfloating raft was deduced and a single-deck floating raft vibration isolator with aliquid level controller were presented based on anti-resonance mechanism.Force'stransmissibility of the raft at various liquid levels and gaps was gotten by experimentswhich verify antiresonance theory of floating raft.With the comparison of thediscrepancy between experimental antiresonance data points and the theoreticalcalculation curve at each gaps and the analysis of different gaps'influence on thatdiscrepancy by combining the theory derivation,it further demonstrates the validity ofthe theoretical model under the condition of hypothesis.The advantages andlimitations of the methods of the tuning gap scheme and the tuning liquid levelscheme were discussed and a combination of the both schemes was suggested for theimprovement of vibration isolation in terms of lower force transmissibility and widerisolation bandwidth.In the actual working condition the vibration frequency is changedThe best damped liquid levels-frequency and Force's transmissibility-frequencycurve is obtained from a large number of experiments.A level regulator has beenmade based on the fact that the excitation frequency is constantly changing underactural working conditions.The control program is programmed with Lab VIEWgraphic language based on the vibration attenuation liquid level curve and combiningthe NI PXI-1602e,sensor and other instruments.The optimal vibration attenuationsituation has been achieved by collecting vibration source signal through the forcesensor,Key Words:quasi-zero-stiffness;permanent magnet spring;nonlinear vibration12